We don't want her to come down to the family room because she wants to fall asleep there. We tell her to go into her room and she becomes frantic, saying she is afraid. This came out of the blue. We don't know what to do with her. I need time to myself at night.
Talk with your daughter about what is causing her to be afraid. Don't worry if she can't tell you, as she may not know or may not be able to put it into words. Ask her what she is afraid will happen. Assure her that you will be down the hall in the family room and ask what she thinks could happen with you sitting close by. Talking through the possibilities will help you understand the fear better and be able to reassure her that the scary things will not happen.
You can do some very basic things to help her get through this. A new nightlight for her room, leaving the door open with the hall or bathroom light on, or leaving a dim light on in her room may help. You could give her a special flashlight that she can turn on herself to check her room when needed.
Your daughter does need to be able to go to sleep by herself. Reassure her that you will be close by, that you will come if she needs you, and that you have confidence that she can overcome this fear. Don't belittle her for this; you can probably remember how real your fears were when you were young. Be sure to praise her in the morning after a successful night.
Many children need a constant routine, and different bedtimes and waking times during the summer are difficult for them. Once school starts and her routine is reestablished this may get easier. She may also be picking up on your need for time to yourself. Reassure her of her importance to you.
If none of the above works, and this continues for a period of months, you may want to ask your daughter's school counselor or pediatrician for a referral to a therapist for further help.